Halogen containing extreme pressure lubricant stabilized with a polyalkylene polyamine



United States Patent HALOGEN CONTAINING EXTREME PRESSURE LUBRICANTSTABILIZED wrrn A POLYALKYL- ENE POLYAMINE V No Drawing. ApplicationJune 20, 1951,

, Serial No. 232,668

Claims. (Cl. 25237.2)

The present invention relates to extreme pressure lubricants of improvedstability against sedimentation. More particularly -it relates tolubricating compositions comprising an extreme pressure halogen compoundand a polyalkylene polyamine.

Halogen containing compounds, particularly chlorinated hydrocarbons, arecommonly employed in lubricating compositions which are required tomaintain lubrication of metal surfaces under high pressures such as areencountered for example in industrial heavy duty bearings and hypoidgears of automotive vehicles. While compounds of this class are veryeffective in producing lubricants of high load carrying capacity, theyhave a disadvantage in that they tend to hydrolyze with the liberationof halogen acid, which is undesirable because of its corrosiveness tometals. Furthermore, such halogen compounds tend to cause increasedsedimentation or sludge formation in the lubricant on standing and inservice which impairs both its appearance and its useful lubricatingvalue.

-It has been proposed heretofore to add to lubricating compositionscomprising such halogenated compounds various types of materials,including amines, which have the property of repressing corrosion byneutralizing the acid formed. For example, McNulty et al. in U. S.2,268,608, disclose that a number of different amines, includingaliphatic amines, benzylamines, ethanolamines, etc., may be employed inextreme pressure lubricants containing halogen compounds, or bothhalogen compounds and sulfur or phosphorus-containing compounds. The useof various amines, including diphenylamine, hexamethylenetetramine andaniline in a lead soap gear lubricant containingboth halogen and sulfurcompounds is disclosed by Hilliker in U. S. 2,386,553.

However, it has been found that the problem of stabilizing a halogenbearing lubricant, such as a gear lubricant, against sedimentation isnot effectively solved by the use of the amines of the prior art. It hasfurther been found that, by the use of an amine selected from aparticular small group of polyalkylene polyamines, such a lubricant isunexpectedly stabilized against sedimentation without impairment of itsother desirable properties including extreme pressure characteristics.

In accordance with the invention, extreme pressure lubricants comprisinghalogen-containing compounds are stabilized by adding to them smallamounts of compounds chosen from the class of polyalkylene polyamineshaving two primary amine groups attached to different aliphatic groups.Suitable compounds of this type may be represented by the generalformula NHz'R(NHR)mNH2, where R is an alkylene group preferablycontaining from 1 to about 6 carbon atoms, and x is an integerpreferably from 1 to about 5. For the sake of simplicity the termalkylene is used in this application to mean any bivalent aliphatichydrocarbon group, including such hydrocarbon groups above ethylenewherein the available valences are terminal or located elsewhere than onadjacent carbon atoms. As examples of the above compounds may bementioned trimethylene tetramine, diethylene triamine, pentamethylenehexamine, triethylene tetramine, tetraethylene pentamine, dibutylenetriamine, tripropylene tetramine, and so forth. Tetraethylene pentaminehas been found to be particularly suitable. Instead of a pure compound,mixtures of these compounds such as are obtained when dihalogencompounds are treated with 2,696,473 Patented Dec. 7, 1954 ammonia, maybe employed. It appears that the ability of these particular compoundsto prevent sludging of the lubricant may be due to some specific actionon inhibiting aromatic or alkylated aromatic compounds, such as forexample halogenated derivatives of parafiin Wax, petroleum' fractions,polymeric materials, benzene, naphthalene, toluene, biphenyl, etc. Thelubricating composition preferably comprises a hydrocarbon lubricatingoil such as a mineral oil fraction containing one or more such compoundsin relatively minor amount. In addition to the halogen-containingcompounds, the lubricant may also contain various other additives of theusual type such as oxidation inhibitors, anti-foam agents, viscosityindex improvers, thickening agents, etc. as Well as other extremepressure agents such as sulfur and/or phosphorus containing compounds.

The amount of the'polyamine inhibitor employed depends upon the amountof halogen in the lubricant composition and upon the instability of thehalogen-containing compound. In general the amount will range from about0.01 to about 1 per cent by weight of the lubricant. Forhalogen-containing extreme pressure lubricants of the usual type theinhibitor is suitably employed in amounts of from about 0.05 to about0.5 per cent, and preferably from about 0.1 to about 0.3 per cent.

A particularly valuable application of the invention is found in theproduction of heavy duty lubricants which contain in addition tohalogenated compounds appreciable amounts of metal salts, such asoil-soluble salts of copper, mercury, lead, etc., which are commonlyadded to compounded lubricating oils and fluid greases to furtherimprove their load carrying properties. In such compositions thedissociation or hydrolysis of the halogenated organic compounds to formfree halogen acid is especially objectionable because it leads toexcessive sludging, which is due largely to the formation of insolublemetal salts by reaction between the halogen acid and the metal compound.

The effectiveness of the stabilizing agents has been demonstrated in theproduction of a very superior halogencontaining lubricant of the abovetype. This is a hypoid gear lubricant containing a lead-chlorine-sulfuradditive combination, which Was found to impart very superior extremepressure and other desirable lubricating characteristics to lubricantcompositions with the exception that an excessive amount of sludge,consisting chiefly of lead chloride, was formed in service and inlaboratory tests at elevated temperatures. As shown by the followingexamples, compositions of very satisfactory stalubricant in a graduatedcentrifuge tube in a constanttemperature oven at 250 F., for periods of4 and 30 hours, then cooling and centrifuging at room temperature at6000 R. P. M. for 45 minutes. The amount of sediment formed wasdetermined from the graduations on the tube.

EXAMPLE 1 A lubricant was prepared by blending as the essentialconstltuents the following materials in the proportions indicated:

- Per cent Lead naphthenate 10,0 Chlorinated paraflin wax 3.0 Sulfurchlorinated sperm oil 10.0

1 Mineral lubricating oil Remainder The mineral lubricating oil employedin the above composition was a blend in approximately a /2 ratio of aparaflinic residuum having an API gravity of 21.9, a flash point, COC,of 570 and an SUS viscosity at 210 F. of 195.2, and a paraflinicdistillate. oil having. an API gravity of 29.4", a flash point, COO, of450 F. and an SUS viscosity at 210 F. of 54.4.

The lead naphthenate, which was prepared from lubricating oil naphthenicacids, had a lead content of 21.0% and an unsaponifiable content of22.8%.

The chlorinated wax was a commercial product sold under the name ofAnglamol 40" by Lubrizol Corporation.

rosion inhibitor.

The sulfur chlorinated sperm oil was a commercial product sold under thename of Sulchlor 55 by Carlisle Chemical Works, Inc. It contained 6.73%of chlorine and 6.76% of sulfur.

To portions of the above lubricant small amounts of various aminesincluding diethylene triamine were added and the compositions testedaccording to the stability test described. The following results wereobtained:

Table l STABILITY TEST [4 hours at 250 F.]

Sediment,

Additive: Percent by volume None I 0.5% triethanolamine 0. 1.0% diphenylamine 0.8 0.5% high molecular weight aliphatic amine 1.5 1.0% highmolecular weight aliphatic amine 8 0.5% diphenyl amine 1.0% diphenylamine 0.5% phenyl alphanaphthylamine 1.0% phenyl alphanaphthylamine 0.1%diethylene triamine 0.5% diethylene triamine 1 Sold commercially underthe trade name Armeen C.

EXAMPLE 2 A lubricant was prepared by blending as the essentialconstituents the following materials in the proportions indicated.

Per cent Lead naphthenate 7.0 Chlorinated paraflin wax 3.0 Sulfurchlorinated sperm oil 7.0 Sulfurized sperm oil 6.5 Mineral lubricatingoil a- Remainder The mineral lubricating oil employed in the abovecomposition was the same as that employed in the lubricant of Example I.

The sulfurized sperm oil was a commercial product sold under the name ofS/V 28 Base by Socony Vacuum Oil Company. It comprised chiefly asulfurized derivative of cetyl oleate and analyzed 9.48% sulfur.

The other additives were the same as those employed in the lubricant ofExample I.

To portions of the above lubricant small amounts of various aminesincluding diethylene triamine were added and the compositions testedaccording to the stability test described. The following results wereobtained:

Table II triethanolamine 1.0 triethanolamine 1.0 high molecular weightaliphatic amine 0.8 high molecular weight aliphatic amine 0. diphenylamine phenyl alpha naphthylamine phenyl alpha naphthylamine 0.1%diethylene triamine 0.5% diethylene triamine 1 Sold commercially underthe trade name Armeen C."

It had a chlorine content of 44.0% and contained. a small amount ofphenoxy propylenev oxide as a cor 4 EXAMPLE 3 A lubricant was preparedby blending as the essential constituents the following materials in theproportions indicated:

Per cent Lead naphthenate 10.0 Chlorinated paraffin wax 1.0 Sulfurchlorinated sperm oil 10.0 Sulfurized sperm oil 5.0 Mineral lubricatingoil Remainder The mineral lubricating oil was a blend in approximatelyequal proportions of an asphaltic residuum having an API gravity of17.0", a flash point, COC, of 645 F. and an SUS viscosity at 210 F. of764, and an asphaltic distillate oil having an API gravity of 253, aflash ptf)ing,7COC, of 335 F. and an SUS viscosity at 210 F. o 3

The additives employed were the same as those of Examples 1 and 2.

To separate portions of the above lubricant small amounts of variousamines including typical compounds of the invention were added and thestability of the resulting compositions determined by the stability testdescribed. The following results were obtained:

Table III STABILITY TEST [4: hours at 250 F.]

EXAMPLE 4 A lubricant was prepared by blending as the essentialconstituents the following materials in the proportions indicated:

The mineral lubricating oil was a solvent refined, clay contacted andlightly acid treated parafiinic wax distillate having an API gravity of27.5, a flash point, COC,

of 490 and an SUS viscosity at 210 F. of 78.6.

The extreme pressure additives were the same as those employed in thelubricants of the previous examples.

To portions of the above lubricant small amounts of tetraethylenepentamine were added and the composi tions tested according to thestability test described for periods of 30 hours. tained:

The following results were ob- Table IV STABILITY TEST [30 hours at 250F.]

Sediment,

Tetraethylene pentamine, per cent: Per cent by volume None 1.0 0.05 0.50.10 0.5 0.20 Trace 0.30 None 0.40 None 0 50 None The following datawere obtained on the load carrying properties of the above lubricants.Lubricant A of Table V below is that of Example 1, lubricant B is thatof Example 2, and lubricant C is that of Example 3.

smears:

Table LOAD CARRYING PROPERTIES Timken Test Lubricant Additive OK 3 lbs.1 p. s. i.

A one 90 37, 750; 42, 500 {51% Dicthylene triamine 85 36, 500; 42, 000 BNone 90 28, 500; 43, 750 {0. 1% Dlethylene triarnine...- 90 31, 500;33,000 None 85 35, 500; 38, 500 C 0. 1% Diethylene triamine 75 34, 500;27, 250 0. 1% Triethylene tetramine 65 37,000; 38.000 0. 1%Tetraethylene pentamin 85 41, 000; 41, 000

The data given in the above tables show that stable lubricatingcompositions comprising ordinarily unstable halogen compounds areobtained by use of the stabilizing compounds of the invention. The datagiven in Tables I, H and III show that the compounds are outstandinglysuperior in stabilizing such compositions as compared with other amineswhich have been proposed heretofore for this purpose. Table V showsfurthermore that the load carrying properties of the halogen-containinglubricant are not appreciably impaired by the compounds in the smallamounts required to impart satisfactory stability to the composition.

In the production of lubricating composit1ons of the type described inthe examples it is to be understood that compounds of similar nature maybe substituted for the extreme pressure agents employed. Thus instead oflead naphthenate, other lead salts such as lead oleate, lead menhadenateor lead resinate may be employed. In place of chlorinated paraffin wax,other halogenated compounds having extreme pressure properties includinghalogenated aliphatic, aromatic, hetero- -cyclic and oxygen-containingorganic compounds such as fatty acids, esters and fatty oils may beemployed. The halogen compound is preferably a highly chlorinatedaliphatic material, containing from about 20 to 45 per cent of chlorine.In place of sulfurized and sulfur chlorinated sperm oil, suitableadditives of this type may be obtained by sulfurizing and sulfurchlorinating other oils such as lard oil, lanolin, corn oil, cottonseedoil, menhaden oil, etc. Also, various types of lubricatlng oils may beemployed, preferably comprising mineral oil fractions obtained by theusual refining methods. The finished composition suitably comprisesabout 3 per cent to about 15 per cent by weight of lead naphthenate orother lead soap, about 1 to 7 per cent of halogenated extreme pressureagent such as chlorinated paraffin wax, about 3 to 10 per cent ofsulfurized fatty 011 and about to 15 per cent of sulfur chlorinatedfatty Oll. S mall amounts of other additives such as oxidationinhibitors, corrosion inhibitors, anti-foam agents, extreme pressureagents, and so forth may also be present.

While the stabilizing agents of the lnvention are employed withparticular advantage in the production of lubricants of the above type,the invention 1s not to be construed as limited to this application,since it 1s obvious that these compounds may be employed in a widevariety of lubricating compositions containing ordinarily unstablehalogen compounds.

Obviously many modifications and varlations of the invention, ashereinbefore set forth, may be made w1thout departing from the spiritand scope thereof, and therefore, only such limitations should beimposed as are indicated in the appended claims.

What is claimed is:

1. A lubricant composition consisting essentially of a minerallubricating oil containing about 1-7% by weight of chlorinated paraflinwax, about 310% by weight of sulfurized sperm oil, about 3-15 by we ghtof sulfur chlorinated sperm oil, about 3-15 by weight of leadnaphthenate and about 0.050.5% by weight of tetraethylene pentamine.

2. A lubricant composition consisting essentially of a hydrocarbonlubricating oil containing a minor amount of an oil-soluble organichalogen containing compound having extreme pressure properties and whichis normally corrosive to metals at elevated temperatures and pressures,and about 0.01 to about 1 per cent by weight of a polyalkylene polyaminerepresented by the general formula 63 NH2R(NHR)NH2, where R is abivalent aliphatic hydrocarbon group containing from 1 to 4 carbon atomsand x is an integer from 1 to 4.

3. A lubricant composition consisting essentially of a hydrocarbonlubricating oil containing a minor amount of an oil-soluble halogenatedaliphatic compound having extreme pressure properties and which isnormally corrosive to metals at elevated temperatures and pressures, andabout 0.01 to about 1 per cent by weight of a polyalkylene Nnzamnmmnzwhere R is an ethylene group and x is an integer from 1 to 3.

4. A lubricant composition consisting essentially of a hydrocarbonlubricating oil containing a minor amount of an oil-soluble chlorinatedaliphatic hydrocarbon compound having extreme pressure properties andwhich is normally corrosive to metals at elevated temperatures andpressures, and about 0.05 to about 0.5 per cent by Weight of apolyalkylene polyamine represented by the general formulaNH2R(HNR)J:NH2, where R is an ethylene group and x is an integer from 1to 3.

5. A lubricant composition consisting essentially of a hydrocarbonlubricating oil as the major component, containing a minor amount of anoil-soluble halogenated aliphatic compound having extreme pressureproperties and which is normally corrosive to metals at elevatedtemperatures and pressures, a minor amount sufficient to impart improvedload carrying properties to the said composition of a lead soap, andabout 0.01 to about 1 per cent by weight of a polyalkylene polyaminerepresented by the general formula NH2R(NHR)CENH2, Where R is a bivalentaliphatic hydrocarbon group containing from 1 to 4 carbon atoms and x isan integer from 1 to 4.

6. A lubricant composition consisting essentially of a hydrocarbonlubricating oil containing about 1 to about 7 per cent by weight of anoil-soluble chlorinated aliphatic hydrocarbon compound having extremepressure properties and which is normally corrosive to metals atelevated temperatures and pressures, about 3 to about 15 per cent byweight of a lead soap, and about 0.01 to about 1 per cent by weight of apolyalkylene polyamine represented by the general formula NH2R(NHR)NH2,where R is an ethylene group and x is an integer from 1 to 3.

7. A lubricant composition consisting essentially of a hydrocarbonlubricating oil as the major component, containing a minor amount of anoil-soluble organic halogen containing compound having extreme pressureproperties and which is normally corrosive to metals at elevatedtemperatures and pressures, a minor amount of an organic sulfurcontaining compound having extreme pressure properties and which isnormally corrosive to metals at elevated temperatures and pressures, aminor amount suflicient to impart improved load carrying properties tothe said composition of a lead soap, and about 0.01 to about 1 per centby weight of a polyalkylene polyamine represented by the general formulaNH2R(HNR)NH2, where R is a bivalent aliphatic hydrocarbon groupcontaining from 1 to 4 carbon atoms and x is an integer from 1 to 4.

8. A lubricant composition consisting essentially of a hydrocarbonlubricating oil as the major component, containing about 1 to about 7per cent by weight of an oilsoluble halogenated aliphatic compoundhaving extreme pressure properties and which is normally corrosive tometals at elevated temperatures and pressures, about 3 to about 10 percent by weight of a sulfurized fatty oil, about 5 to about 15 per centby weight of a sulfur halogenated fatty oil, about 3 to about 15 percent by weight of a lead soap, and about 0.01 to about 1 per cent byweight of a polyalkylene polyamine represented by the general formulaNH2R(NHR)ZNH2, where R is an ethylene group and x is an integer from 1to 4.

9. A lubricant composition consisting essentially of a hydrocarbonlubricating oil as the major component, containing a minor amount of anoil-soluble organic halogen containing compound having extreme pressureproperties and which is normally corrosive to metals at elevatedtemperatures and pressures, a minor amount sufiicient to impart improvedload carrying properties to the said composition of a lead soap, andabout 0.01 to about 1 per cent by Weight of a polyalkylene polyaminerepresented by the general formula NH2R(NHR)NH2, where R is an ethylenegroup and x is an integer from 1 to 4.

matters 7 SV 10. A lubricating composition consisting essentially ofabout 1 per cent by weight of a polyalkylene polyamine a hydroear-bonlubricating oil as the major component, represented by the generalformula NH2R(NHR):NH2,

containing a minor amount of an oil-soluble organic; haloe where R is anethylene group and x is an integer from gen containing oompouncl havingextreme pressure propl to 4.

erties and which is normally corrosive to metals at ele-. 5

vatecl tempgratures and pressures, at lr lr inor amount of an ReferencesCited in the file of this patent, ga i su Hr c t ning eo poun. ay n exteme n essure properties and which is normally eorrosive to metals UNITEDSTATES PATENTS at elevated temperatures and pressures, a minor amountNumber Name Date sufficient to impart improved load earrying propertiesto 10 2,268,608 McNulty et a1. Jan. 6, 1942 the said composition of alead soap, and about 0.01 to

9. A LUBRICANT COMPOSITION CONSISTING ESSENTIALLY OF A HYDROCARBONLUBRICATING OIL AS THE MAJOR COMPONENT, CONTAINING A MINOR AMOUNT OF ANOIL-SOLUBLE ORGANIC HALOGEN CONTAINING COMPOUND HAVING EXTREME PRESSUREPROPERTIES AND WHICH IS NORMALLY CORROSIVE TO METALS AT ELEVATEDTEMPERATURES AND PRESSURES, A MINOR AMOUNT SUFFICIENT TO IMPART IMPROVEDLOAD CARRYING PROPERTIES TO THE SAID COMPOSITION OF A LEAD SOAP, ANDABOUT 0.01 TO ABOUT 1 PER CENT BY WEIGHT OF A POLYAMINE REPRESENTED BYTHE GENERAL FORMULA NH2R(NHR)INH2, WHERE R IS AN ETHYLENE GROUP AND X ISAN INTEGER FROM 1 TO 4.